bug#75116: [PATCH] Make 'yank-media' autoselect the best media type

[Eli Zaretskii <eliz@gnu.org>]

> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: visuweshm@gmail.com, 75116@debbugs.gnu.org, pinmacs@cas.cat,
>  rpluim@gmail.com
> Date: Mon, 06 Jan 2025 19:05:20 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> >>>     User asks to autoselect:
> >> >>>       1. autoselect-function (a-s-f) returns one media type: we yank it.
> >> >>
> >> >> Yes.
> >> >>
> >> >>>       2. a-s-f returns multiple media types: we ask the user which one
> >> >>>          to yank.
> >> >>
> >> >> No, we use the first one.
> > ...
> > That's what I mean by "ask": use the default behavior of the command.
> >
> > Conceptually, it's the same as the paste operation in other
> > applications: by default, the application decides which of the formats
> > to use, and if the user wants to choose, he/she needs to pop up a menu
> > of available formats in some way and select from there.
> 
> I see the logic.
> 
> I still find returning a list of mimetypes useful though - if user wants
> to implement an additional filter on top of a-s-f provided by major
> mode, having a list of mimetypes as input is more flexible.

We could leave the selection to the command level, and have the
function return a list in all the cases.

> But we need to document that the final choice will be taken as the first
> element from what a-s-f (possibly adviced) returns.

Under the default behavior of auto-selecting one type, yes.  The
function should therefore arrange for the first type to be the most
reasonable/useful one.